Peripheral nerve field stimulator curved subcutaneous introducer needle with wing attachment specification

ABSTRACT

An apparatus for use in peripheral nerve field stimulation (PNFS) whereby a plurality of curved introducer needles, of varying curvatures, are provided to permit the physician to best locate the region of oligodendrocytes that contain the A Beta fibers by matching the lumbar lordosis. A wing device is also provided that is attachable to the hub of the curved needle introducer which gives the physician better ability to maneuver the needle during insertion as well as permitting tenting of the skin. The invention benefits a large number of painful disorders arising from pathology in the cervical, thoracic, and lumbar spine. In addition, this invention can also help a large number of other conditions including but not limited to failed back surgery syndrome/post-laminectomy pain, occipital/suboccipital headaches, scar pain, post herpetic neuralgia pain, mononeuritis multiplex, and pain following joint surgery (e.g., knee, hip, shoulder).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/464,470, filed May 12, 2009, which claims the benefit of U.S.Provisional Application No. 61/052,464, filed May 12, 2008, which isincorporated herein by reference.

FIELD OF INVENTION

The current invention relates to surgical methods, and moreparticularly, to a neuromodulation device.

BACKGROUND

Peripheral Nerve Field Stimulation (PNFS) is a rapidly growing area ofneuromodulation that has shown significant promise in treating patientswith cervical, thoracic, and lumbar pain. This procedure, however, hasrelied on using electrical leads designed for stimulation of the dorsalcolumn of the spinal cord despite the reputed target neural elementbeing a vastly different structure. In peripheral nerve fieldstimulation, the neural elements that are targeted for depolarizationare the terminal dendrocytes located in the subcutaneous region of thepatient.

This specific type of neuromodulation is discussed in particular detailin A Case Report of Subcutaneous Peripheral Nerve Stimulation for theTreatment of Axial Back Pain Associate with Postlaminectomy Syndrome, byKrutsch, M D, et al., Neuromodulation: Technology at the NeuralInterface, Vol. 11, Number 2, 2008.

The introducer needle most widely used by peripheral nerve fieldstimulation implanters is a straight 14 gauge 4½ inch Touhy epiduralneedle designed for a loss of resistance approach to enter the epiduralspace rather than placement of electrodes into the subcutaneous region.However, achieving the proper placement of the distal end of the Touhyepidural needle for use during PNFS is very difficult for a number ofreasons. The straight needle goes far too deep into the dermis orsubcutaneous tissue. In addition, the small surface area of the proximalend of the Touhy epidural needle does not give the physician therequired gripping surface area to properly manipulate the distal end ofthe needle. Furthermore, because of the straight shape of the Touhyneedy, the clearance between the needle's proximal end and thephysician's fingers with the skin surface make it difficult for thephysician to maneuver the needle.

Thus, there remains a need for an apparatus for use in peripheral nervefield stimulation (PNFS) that permits the physician to best locate theregion of oligodendrocytes that contain the A Beta nerve fibers forinserting an electrical lead therein.

All references cited herein are incorporated herein by reference intheir entireties.

BRIEF SUMMARY

An apparatus for supporting peripheral nerve field stimulation (PNFS) ofliving being tissue is disclosed. The apparatus comprises: an introducerhaving a curved portion; a stylet having a curved portion that issimilar to the curved portion of the introducer so that the stylet canbe inserted within the introducer to form an introducer needle assembly;and wherein the introducer needle assembly provides a passageway throughthe living being tissue for positioning an electrical lead in a regionof oligodendrocytes that contain A Beta fibers when the curved portionof the introducer is passed through the living being tissue and thestylet is removed. In addition, the introducer needle will have a novel“wing-attachment” device that further facilitates the implantingphysician to properly position the lead near the A Beta fibers.

A method for positioning an electrical lead within living being tissueto support peripheral nerve field stimulation (PNFS) is disclosed. Themethod comprises: (a) inserting an introducer needle assembly having acurved portion through the skin of a living being at an entry locationdisplaced away from a target region requiring PNFS; (b) providing atactile indication of a tip of the curved introducer needle assembly asthe tip moves toward the target region, and wherein the target regioncomprises oligodendrocytes that contain A Beta fibers; (c) tenting theskin at the entry location as the tip is moved toward the target region;(d) removing an insertable portion from the introducer needle assembly;and (e) inserting an electric lead through the introducer needleassembly so that a distal end of the electrical lead is positioned underthe target location in preparation for PNFS.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements andwherein:

FIG. 1 is an enlarged exploded view of the present invention showing thestylet, the introducer and the electrical lead (also referred to as a“PNFS lead”);

FIG. 2 is an enlarged cross-sectional view of the present inventiontaken along line 2-2 of FIG. 1 and showing the stylet inserted in theintroducer;

FIG. 3 is an enlarged cross-sectional view of the present inventiontaken along line 2-2 of FIG. 1 showing the electrical lead replacing thestylet and inserted within the introducer;

FIG. 4 is an enlarged cross-sectional view of the wing attachmentinstalled on the introducer and taken along line 4-4 of FIG. 1;

FIG. 5 is an enlarged longitudinal cross-sectional view of theelectrical lead taken along line 5-5 of FIG. 1;

FIG. 6 is an enlarged transverse cross-sectional view of the electricallead taken along line 6-6 of FIG. 5;

FIG. 7 shows three exemplary embodiments of the present invention havingdifferent angles of curvature;

FIG. 8 shows how the present invention is initially used in the PNFSprocedure, by marking the area of over the pain on the skin and markingthe area for inserting the present invention;

FIG. 9 depicts how the physician grasps the present invention just priorto insertion into the body;

FIG. 10 depicts how the physician “tents” the skin during insertion ofthe present invention;

FIG. 11 depicts how the physician guides the proximal end of the presentinvention under the skin toward the target region;

FIG. 12 depicts the present invention, with the stylet removed, and theelectrical lead being inserted through the introducer for positioning atthe target region;

FIG. 13 depicts how the physician removes the introducer once theelectrical lead is properly positioned;

FIG. 14 depicts how the electrical lead is totally embedded in theliving being and connected to an embedded power source (e.g., a battery)at another location, e.g., in the buttocks;

FIG. 15 depicts an alternative application wherein the electrical leadis partially embedded in the living being with a portion emerging fromthe living being for connection to an external power source (not shown);and

FIG. 16 is a cross-sectional view of the target region showing theinsertion of the present invention for properly locating the electricallead in the region of oligodendrocytes that contain the A Beta fibers.

DETAILED DESCRIPTION

The invention 20 of the present application of a peripheral nerve fieldstimulator (PNFS) introducer needle with winged attachment is a usefulinvention that benefits a large number of painful disorders arising frompathology in the cervical, thoracic, and lumbar spine. In addition, thisinvention 20 can also help a large number of other conditions includingbut not limited to failed back surgery syndrome/post-laminectomy pain,occipital/suboccipital headaches, scar pain, post herpetic neuralgiapain, mononeuritis multiplex, and pain following joint surgery (e.g.,knee, hip, shoulder).

In particular, as shown in FIG. 1, the present invention 20 comprises aninsert 22 (hereinafter known as a “stylet”) that is insertable within alumen 24 (hereinafter known as an “introducer”). Both of thesecomponents comprise beveled flat tips 26 and 28 respectively at theirdistal ends. The distal tip of the introducer needle could be eithersharp or blunt but for illustration purposes is shown as sharp. Thedistal end 28 of the introducer 24, unlike the stylet 22, is open. Whenthe stylet 22 is inserted into the introducer 24, the present inventionforms an introducer needle assembly 20.

The introducer needle assembly 20 is similar in many ways to a 14 gaugeTouhy epidural needle but is unique in its shape. As can be seen inFIGS. 1 and 7, the present invention 20 is curved. By way of exampleonly, some preferred angles of curvature are 15° (see 20A), 25° (20B)and 35° (20C). Both the stylet 22 and the introducer 24 have curvedportions 22A and 24B, respectively, as most clearly in shown in FIG. 2,for reasons which will be discussed shortly. Suffice it to say thatgiven that the spine normally has significant lordotic and kyphoticcurves, having a curved needle better allows the implanting physician tomaintain the same plane in the subdermal region wherein the A Betafibers lie.

Although the example embodiment has been described in terms of a needlehaving properties similar to a 14 gauge Touhy needle, those skilled inthe art will understand the present invention 20 can include larger andsmaller gauge needles, as well as needles with different tips andcompositions including but not limited to the Galt Micro Access tearaway (model 010-14) and Iflow 17 gauge needle (model #5001376).

By way of example only, the length of the introducer needle assembly 20is approximately 3.5-6 inches. Furthermore, the introducer 24 furthercomprises an attachable grip 30 at the introducer's proximal end 32. Thegrip 30 (also referred to as a “wing attachment”) permits the physicianthe ability to more firmly grasp the present invention 20 and to bettermanipulate it during the PNFS procedure. The wing attachment provides abetter gripping and maneuvering surface for the physician implanter toplace pressure posteriorly (towards the epidermal layer) once the needleis in the subdermal layer which helps separate the subdermal layer thatis rich in A Beta fibers from the dermis and fascial layers (FIG. 16).The grip 30 is severed 31 to permit its releasable attachment to theinsertion collar or hub 33 of the introducer 24. For example, to installthe grip 30, the grip 30 is slid over the distal end 28 of theintroducer 24 and then firmly pushed over the insertion collar or hub 33until it is positioned as shown in FIG. 1. This makes a snug fit ontothe introducer 24. The grip 30 includes a pair of transverse elements or“wings” 35A and 35B that provide the physician with finger grips forprecisely manipulating and controlling movement of the introducer needleassembly 20. The winged attachment may be of many different shapesincluding rectangular, square, circular oblong, and triangular. The wingattachment may be composed of a flexible material such as a plasticpolymer, rubber, or malleable metal to further facilitate the implantingphysician to grip the introducer and allow for clearance between theintroducer and the implanting physicians fingers given that thesubdermal layer is often in close approximation to epidermis. The wingattachment may also have a gripping surface such as treads or anti-skidcoating material to enable the implanter to better hold the introducerneedle. The wing attachment can be attached to the introducer needle ina variety of manners including snapping on, slipping on, clamping on, orclipping on. In addition, the wing device may be attached by othermethods including using a glue or tape adhesive material. The wingattachment could even be comprised of a thickened sleeve that would fitaround the hub of the Touhy needle. Our description is only one of manyways to attach the wing device for illustration purposes.

It should also be noted that with the grip 30 installed on the hub 33,there is an existing key that permits the physician to “track” therelative position of the curved shaft 24A when inserted into livingbeing tissue. In particular, as shown most clearly in FIG. 1, the stylet22 includes a hub 21 having a nub 23. When the stylet 22 is properlyinserted into the introducer 24, the nub 23 fits into a recess 25 in theintroducer hub 33. This can also be seen in FIG. 2. When the nub 23 isfitted into the recess 25, the distal end 28 of the introducer 24 pointsupward, as shown in FIG. 2. Thus, if the physician rotates theintroducer 24 about its longitudinal axis, he/she is always aware ofwhich direction the curved distal end 28 is positioned by noting wherethe nub 23 is positioned.

As will also be discussed shortly, once the introducer needle assembly20 is inserted into its proper location in the body, the stylet 22 isremoved and an electrical lead (also referred to as a “PNFS lead”) 34 isinserted into the introducer 24. Once the distal end 36 of theelectrical lead 34 is positioned under the skin 10 at the proper targetlocation, the introducer 24 is removed and the electrical lead 34 issecured to the skin 10. The proximal end 38 of the electrical lead 34 iselectrically coupled to a power source, e.g., an external power source(not shown) or to an implanted power source 40 (FIG. 14).

It should be understood that a wide variety of medical leads 34 can beused with the present invention 20 and the invention 20 is not limitedto any particular type of medical lead 34. By way of example only, onetype of medical lead that can be used with the present invention 20 isan electrical lead such as the Quattrode® #3063 manufactured by AdvancedNeuromodulation Systems of Plano, Tex. As can be seen in FIGS. 1 and 5,the electrical lead 34 comprises a plurality of electrode elements thatare in electrical communication with respective electrodes via internalconductors 42, as shown by the reference numbers 41A-41B, 42A-42B,43A-43B, etc. When positioned properly, there may be a 5 cm distancebetween the most proximal and distal electrode. When energized,localized current passes between corresponding electrode elements andthrough the closely-adjacent subdermal tissue. However, as mentionedpreviously, a wide variety of electrical leads 34 can be used with theinvention and therefore, the phrase “electrical lead 34” as usedthroughout this application is meant to include all such types ofmedical leads and is not limited to that shown in the various figures.For example, another medical lead, such as the Pisces-Octad™ #3788 soldby Medtronic, Inc. of Minneapolis, Minn., can also be used.

As can appreciated by those skilled in the art, the stylet 22, whilepositioned in the introducer 24 when the introducer needle assembly 20is pushed through the skin layers, the stylet 22 is a solid member thatacts to prevent body fluids and tissue from lodging in the introducer24, thereby preserving the passageway that is formed by the presence ofthe introducer 24 for eventual displacement by the electrical lead 34.

As mentioned previously, the introducer needle most widely used byperipheral nerve field stimulation implanters is a straight 14 gaugeTouhy epidural needle designed for a loss of resistance approach toenter the epidural space rather than placement of electrodes into thesubcutaneous region. In PNFS, placement of the electrodes in theelectrical lead 34 closest to the target neural elements is bestrealized by entering the subcutaneous region with the patient in theprone position and “tenting” the needle by placing posterior pressurewhile advancing to the region of the patient's maximal pain. Theplacement of posterior pressure once the needle has entered thesubdermal layer helps to separate the subdermal layer from the dermisand muscle fascial layer while advancing the needle thereby placing thelead within the layer that contains the highest concentration of A Betafibers. “Tenting” is a novel technique that enables the implantingphysician to more consistently place the electrical lead in thesubdermal region. The invention described herein facilitates this noveltechnique. When done properly, there is minimal resistance and oftenthis layer has an abundance of A Beta fibers allowing maximalstimulation for PNFS which ultimately maximizes pain relief for thepatient.

Heretofore, the use of the straight Touhy needle does not effect theproper placement. In contrast, the use of the curved introducer needleassembly 20 permits this proper placement, e.g., the curved portion22A/24A matches the normal lumbar lordosis present in patients withgreater than 90% of patients having a lumbar lordosis of 29-37 degreesoff of the sagital plane.

FIGS. 8-14 show an exemplary sequence for achieving positioning theelectrical lead 34 using the invention 20 of the present application.With the patient positioned in a prone position, the physician marks onthe skin 10 the location under which the electrode distal end 36 ideallyneeds to be positioned; also referred to as the target location 44 (FIG.8). At another location on the skin (e.g., 3.5-4.5 inches away from thetarget location 44), the physician marks the incision point where asmall incision is made in the skin. For example, an 11-blade scalpel isused to make a 0.5 cm incision 46. This avoids trauma that wouldnormally occur if the distal end 28 of the introducer needle assembly 20were simply used to make the initial puncture. With the incision 46, thephysician grasps the introducer needle assembly 20 (i.e., the stylet 22is already inserted therein and the grip 30 has also been previouslycoupled to the hub 33) as shown in FIG. 9; as can be seen, the physicianis able to much more easily manipulate the introducer needle assembly 20by applying force through his middle and ring fingers on the respectivewings 35A/35B thereby “tenting” the skin and separating the dermis fromthe muscle fascial layer to place the needle in the subdermal regionwhere the A Beta fibers are located.

As the physician continues to insert the introducer needle assembly 20into the skin 10 towards the target region 44, the curved portion 24A ofthe introducer rides close to the skin surface, permitting the physicianto obtain a tactile indication of the distal end 28 with his/her otherhand, as shown in FIG. 10. This has not been possible with the use ofthe straight Touhy needle. It should also be noted that during thisprocess, the physician is applying a slightly upward force to “tent” theskin (see reference number 48) at the entry location 46. As mentionedearlier, this “tenting” involves placing posterior pressure whileadvancing to the region of the patient's maximal pain. By tenting and byusing his/her other hand to guide the distal end 28 of the introducerneedle assembly 20 to the proper subdermal location, the physicianprevents the distal end 28 from accidently piercing and exiting the skin10 or going to deep and entering the muscle tissue. Thus, as mentionedpreviously, having the attachable grip 30 facilitates the application ofposterior pressure and allows for the “tenting” which in turn allowsefficient and more reliable placement in the subcutaneous region.

Once the distal end 28 of the introducer needle assembly 20 arrives atthe subdermal location beneath the target location 44, the physicianremoves the stylet 22 (see FIG. 11) from the introducer 24 (withoutdisplacing the distal end 28 of the introducer 24 from the subdermallocation) while tenting the skin 10 at the incision 46.

Next, as shown in FIG. 12, the physician inserts the electrical lead 34into the introducer 34 until the distal end 36 of the lead 34 ispositioned in the desired subdermal location. FIG. 16 depicts how theintroducer 24 is oriented for positioning the electrical lead 34 in theregion of oligodendrocytes that contain the A Beta fibers.

While continuing to tent the skin 10, the physician removes theintroducer 24, as shown in FIG. 13, leaving the electrical lead 34 inplace. The electrical lead 34 is then secured in place (e.g., sutured(not shown), etc.), as shown in FIG. 14. The proximal end 38 of theelectrical lead 34 is then electrically connected to an implanted powersource, e.g., a rechargeable battery (e.g., 1.5 cm×5 cm×5 cm) that isimplanted in, e.g., the buttocks 12 (2 cm deep) to begin the PNFS.Alternatively, a portion of the electrical lead 34, including itsproximal end 38, are not embedded in the living being and emerge fromthe skin 10 to permit the proximal end 38 to be electrically coupled toan external power source (not shown) to begin the PNFS.

By way of example only, kits may be supplied with three differentpre-curved needles at approximately 15° (see 20A), 25° (20B) and 35°(20C) angles of curvature. A measuring tape with a marked length (forexample, 4.5 inches), to facilitate positioning of the PNFS lead mayalso be included with the kit. In addition, having markings on themeasuring tape to correspond to current lead arrays electrode toelectrode distances will better enable to implanting physician to coverthe patient's region of pain.

Thus, using the present device and method of the present invention 20,this allows physicians to better introduce the PNFS electrical lead 34near the oligodendrocytes that contain the A Beta fibers by matching thenormal kyphosis and lordosis present throughout the spine, as well asthe curvature in the occipital region. In addition, the inventionbenefits a large number of painful disorders arising from pathology inthe cervical, thoracic, and lumbar spine. In addition, this inventioncan also help a large number of other conditions including but notlimited to failed back surgery syndrome/post-laminectomy pain,occipital/suboccipital headaches, scar pain, post herpetic neuralgiapain, mononeuritis multiplex, and pain following joint surgery (e.g.,knee, hip, shoulder).

While the invention has been described in detail and with reference tospecific examples thereof, it will be apparent to one skilled in the artthat various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

1-19. (canceled)
 20. A device for implanting an electrical stimulationlead for peripheral nerve stimulation within a living being, the devicecomprising: an elongated curved stylet having a proximal end and adistal end; a first hub attached to the proximal end of the stylet, thefirst hub having a generally rectangular prism shaped first portion witha nub extending from a first edge of the first portion, the first hubincluding a generally rectangular prism shaped second portion connectedto the first portion; an elongated curved introducer having a proximalend and a distal end, the introducer for receiving therein the stylet; asecond hub attached to the proximal end of the introducer, the secondhub having a generally rectangular prism shaped first portion, the firstportion of the second hub having a first face with the second hubattached at the first face to the proximal end of the introducer, thesecond hub including a second portion extending from a second face ofthe first portion, the second face being distal and opposite the firstface of the second hub, the second portion including a recess, therecess being shaped and sized to mate with the nub extending from thefirst edge of the first portion of the first hub, such that when thestylet is inserted into the introducer, the nub mates with the recess;and a grip, the grip being hollow and generally rectangular prismshaped, the grip having two opposing open ends, the grip having a firstside, the first side being severed the length of the first side betweenthe two open ends, the grip sized and shape to be releasably attached toand over the second hub with the severed first side facilitating theattachment and removal of the grip with the second hub; and the gripincluding a first generally planar wing extending generallyperpendicular from a second side of the grip, the first wing for atleast facilitating the manipulation of the introducer by the fingers ofa user.
 21. The device of claim 20, wherein the grip includes a secondgenerally planar wing extending generally perpendicular from a thirdside of the grip.
 22. The device of claim 21, wherein the third side ofthe grip is opposite the second side of the grip.
 23. The device ofclaim 20, wherein each of the stylet and the introducer are curved at anangle of curvature between 15° and 35°.
 24. The device of claim 20, andfurther including an indicator at a proximal end the introducer thatpermits a user to track a relative orientation of the introducer whenthe introducer is passed through portions of the living being.
 25. Anapparatus for implanting an electrical stimulation lead for peripheralnerve stimulation within tissue a living being, the device comprising:an elongated stylet having a proximal end and a distal end and a curvedportion intermediate the proximal end and the distal end; a first hubattached to the proximal end of the stylet, the first hub having agenerally rectangular prism shaped first portion with a nub extendingfrom a first edge of the first portion, the first hub including agenerally rectangular prism shaped second portion connected to the firstportion; an elongated introducer having a proximal end and a distal end,and a curved portion intermediate the proximal end and the distal end ofthe introducer, the introducer for receiving therein the stylet, withthe angle of curvature of the curved portion of the introducer being thesame as the angle of curvature of the curved portion of the stylet; asecond hub attached to the proximal end of the introducer, the secondhub having a generally rectangular prism shaped first portion, the firstportion of the second hub having a first face with the second hubattached at the first face to the proximal end of the introducer, thesecond hub including a second portion extending from a second face ofthe first portion, the second face being distal and opposite the firstface of the second hub, the second portion including a recess, therecess being shaped and sized to mate with the nub extending from thefirst edge of the first portion of the first hub, such that when thestylet is inserted into the introducer, the nub mates with the recess;and a grip, the grip being hollow and generally rectangular prismshaped, the grip having two opposing open ends, the grip having a firstside, the first side being severed the length of the first side betweenthe two open ends, the grip sized and shape to be releasably attached toand over the second hub with the severed first side facilitating theattachment and removal of the grip with the second hub; and the gripincluding a first generally planar wing extending generallyperpendicular from a second side of the grip, the first wing for atleast facilitating the manipulation of the introducer by the fingers ofa user.
 26. The apparatus of claim 25, wherein the grip includes asecond generally planar wing extending generally perpendicular from athird side of the grip.
 27. The apparatus of claim 26, wherein the thirdside of the grip is opposite the second side of the grip.
 28. Theapparatus of claim 27, wherein the curved portions of each of the styletand the introducer are curved at an angle of curvature between 15° and35°.
 29. The apparatus of claim 28, and further including an indicatorat a proximal end the introducer that permits a user to track a relativeorientation of the introducer when the introducer is passed throughportions of the living being.